【摘要】 为检测牛传染性鼻气管炎病毒(IBRV)抗体在免疫牛体内的产生及其消长规律,评价IBRV LNM株致弱疫苗的保护效力,并确定免疫持续期,本实验对免疫试验组牛每头颈部肌肉接种制备的IBRV LNM株致弱疫苗104.5 TCID50/mL,监测血清抗体效价,进行免疫期的确定。在疫苗免疫后的6个月、9个月和12个月分别抽取3头免疫组和两头对照组牛采用IBRV-LN01/08强毒株进行攻毒试验,每头牛的攻毒剂量为107.0 TCID50/mL。结果显示疫苗免疫后12个月时,中和抗体效价仍维持在1∶11以上。攻毒结果显示3个时间点强毒攻击后,疫苗对免疫牛均具有良好的保护力。研究表明IBRV弱毒疫苗可有效地保护免疫牛抵抗IBRV强毒株的攻毒,其免疫持续期最少为12个月。更多还原

【Abstract】 This study was designed to evalutate neutralizing(SN) antibodies against infectious bovine rhinotracheitis virus(IBRV) in the calves vaccinated with the attenuated IBRV vaccine.A total of 15 healthy calves at weaning were randomly divided into two groups,with 9 calves in vaccinate group and 6 in control group.The attenuated IBRV LNM vaccine strain was administrated via intramuscular injection on the neck at a single dose of 1mL and challenged with a virulent IBRV-LN01/08 virus by nasal spray.The blood samples were collected at different time points for monitoring SN antibody titers.The results indicated that the SN antibody titers in the vaccinated calves maintained at a relative high level until 12 month post-vaccination,and the vaccinated calves were effectively protected from the challenge,as detected by the clinical scores,virus shedding and rectal temperatures.Therefore,the duration of immunity of the vaccine was at least for 12 months.更多还原